Super capacitors running 16 Ohm motor for 20 Minutes

[ImUrtastyflava]

How long does it take to charge it up with 12 volts?

And if I used 12 volt how long will it last? Will it last for a long time?

[FaradayToRemember]

Whats up with Mouser charging a $100 hazardous material fee with supercaps? Not one other seller (Digikey, EGM, etc) charges this. Anyways, my 1.75A supply @12v will charge my five Maxwell "D-cell" 350F caps in series (total 12.5v@70F) in 8 minutes...25mV/sec gives me a delta of 12v/0.25=480 seconds = 8 minutes...assuming the charge rate is constant and its a full 1.75A, probably not > <. but anyways, SUBSCRIBED and also 5* rating for bashing the silly joule thief! THANK YOU!

[trailkeeper]

Nice. About how long will a typical white LED last when connected to that? I also guess if it's charged up to a higher voltage than that required for the LED a voltage rugulator can be used to extend the time it is turned on.

[patrickikis]

@trailkeeper

Days.... Literally Days. I'd use a 5v regulator and a 470R resistor. Days =)

[trailkeeper]

@patrickikis Ok, thanks, also a "Joule Theif" (voltage stepup circuit) can light an LED on very low voltages where it would normally not light. Probably good to have a larger capacitor when doing/making something like a hand or bicycle cranked generator where your charging some batteries that cannot take too much current at once, hence I think it will allow the cranking of the generator to actually go slower since power is already stored for recharging.

[gushhnet]

@trailkeeper "joule thief" is extremely inefficient and it's just an introductory project to electronics, alas a bad one since most of the people can't even explain what it is or why it works leading them to a plethora of ridiculous assumptions.

[trailkeeper]

@patrickikis Ok, that circuit would work good. The LM317 chip/IC is a three pin/terminal adjustable voltage regulator that takes few parts (maby an external resistor). I think it will go down to about 1.2 Vdc and as high as about 30 Vdc. I guess if its set to the voltage of that needed by the LED, then no resistor will be needed. It can supply up to 1.5A of current too. It's great to get projects up and running quickly.

[patrickikis]

@trailkeeper

Hi

Yeah, I work with them all the time. I sell LM317 kits on my ebay store. I would use the LM7805 because you don't really need any external components, expect for maybe some caps (But in this case you wouldn't need them) -)

[reviathon360]

Wow. 50 Farad? My 470 uF is that big. But it is at 200wv.

[patrickikis]

@reviathon360

Yes, the 50f unit has a low voltage rating of 2.7v, which is why you have to string them in parallel and series if you want to get a useful voltage/power rating. Lots of fun to play with! Thanks for commenting!